Неотропический речной выдра (Lontra longicaudis)

Species of mammal

The Neotropical otter or Neotropical river otter (Lontra longicaudis) is an otter species found in Mexico, Central America, South America, and the island of Trinidad. It is physically similar to the northern and southern river otter, which occur directly north and south of this species' range. Its head and body length can range from , plus a tail of Body weight ranges from Otters are members of the family Mustelidae, the most species rich (and therefore diverse) family in the order Carnivora. This otter is found in many different riverine habitats, including deciduous and evergreen forests, savannas, llanos and pantanal. It prefers to live in clear fast flowing rivers and streams. It is a relatively solitary animal and feeds mostly on fish and crustaceans.

The taxonomy of the genus Lontra has been debated, but the use of Lontra rather than Lutra for New World otters is generally supported. The Neotropical otter has a very wide range, covering a large portion of South America, so it is not surprising there are geographical structures separating some populations. One such geographical isolation is the Cordillera Mountains. Additionally, the river in the Magdellena river valley flows north, away from the mountains, decreasing the likelihood that otters in the northern tip of South America will mix with otters elsewhere in the continent. Neotropical otters have an unusual phylogenic relationship to other otter species. They are most similar to marine otter (Lontra felina) and southern river otter (Lontra provocax), which is not surprising considering these two species are found in South America. However, Neotropical otters are relatively distantly related to giant otter (Pteronura brasiliensis), which is surprising considering they have nearly identical ecological niches and home ranges.

The Neotropical otter has the widest distribution of all the Lontra species. Their habitat can range from northwest Mexico to central Argentina. They prefer clear, fast flowing rivers, and are rarely known to settle in sluggish, silt laden lowland waters or boggy areas. While mostly occurring at above sea level, they have been found settled at They require dense riparian vegetation and abundant den sites but, other than that, the Neotropical otter is very versatile and tolerant to environmental change. The otters prefer den sites that are solid, high, dry, and in proximity to deep water.

The Neotropical otter's diet consists mostly of fish and crustaceans making up 67% and 28%, respectively, of its total diet. The otter will also occasionally feed on mollusks and small mammals, as well as birds, large insects and fruits. This otter is known to occasionally attack fishnets for a source of prey, hindering fishing productivity.

Breeding occurs mostly in spring. Gestation will last 56 days and produce a litter of 1–5 pups. The male will only spend a single day with the female during breeding season. The female must keep her pups safe from predation by other Neotropical otters. In one captive breeding situation, cannibalism by the mother may have occurred, though it was not confirmed. In an ecologically healthy area, there are many possible shelters so an individual can choose its preferred den. However, studies show that not all possible shelters are occupied and not all shelters are equally utilized by Neotropical otters. Otters visit different shelters with varying frequencies, from once or few times per up to many times per year. One factor that influences their preference for a den has to do with the water level, especially during flood season, when a den near water level can easily be washed away. A den may be at the water level, near the bank, or more than 1.5 meters about the water level. Neotropical otter females will rear pups in a den without a male. In some cases, a female may find a den that has space to keep her pups and a separate area for her own space. A study of a male otter's movement over 35 days showed he used three different dens without communication between them. Also, this individual moved between two islands separated by a one kilometer wide estuary. He spent some time in a site with heavy mud, poor substrate for a den, so he may have been on the move to find food. Dens may have more than one opening, so the otter can easily exit to forage for food while staying safe from predators. There are many classifications of dens that Neotropical otters may use. A cavity among stones or under tree roots is preferred. In certain parts of South America, an otter may come across a limestone dissolution cavity or a cavity in a rocky wall. Though lacking a source of light, the Neotropical otter can make great use of this sturdy home. As a last resort, an otter expend energy to excavate a space among vegetation or a river bank, though those homes are less sturdy. Vegetative cover is also very important for the Neotropical otter. In comparison to other otter dens, the Neotropical otter dens do not have holes directly into the water, they do not use plant material as bedding, and will live in caves without light. They are elusive creatures and prefer undisturbed forests without signs of human activity. When humans clear forests for agricultural land, the number of available otter habitats plummets. Signs of marking may be most concentrated around their dens. They tend to only mark in certain areas of the den, separate from the activity center of the den. In caves, where a water sources may leak through the walls and wash away the scent, the resident may mark areas inside their den.

The niches and ranges of the giant otter and the Neotropical otter overlap widely. Both species are diurnal and mainly piscivorous. The giant otter is less of a generalist in habitat, preferring slow moving water and overhanging vegetation, but where the Neotropical otter may also occur. The giant otter is much larger and hunts in groups, so it can take larger prey. Some areas, like the Pantanal, have high enough productivity such that both otter species can coexist with little or no competition (niche partitioning). Additionally, Neotropical otters prefer deeper and wider streams than giant otters.

The Neotropical otter is listed as Near Threatened by the IUCN. The species is currently protected in Argentina and many other South American countries. Heavy hunting for its fur in the 1950s–1970s resulted in much local extinction over the otter's range. Illegal hunting, habitat destruction through mining and ranching, and water pollution still affect the population of the Neotropical otter. Although there have been attempts at captive breeding, these attempts have been largely unsuccessful. Neotropical otters are threatened by habitat degradation associated with: agriculture, soil compaction, pollution, roadways, and runoff. Also, when forests are cleared for cattle grazing, heavy vegetation (which is the otter's preferred habitat) near streams is also cleared or trampled by cattle. This species is a very important ecological indicator because they prefer ecologically rich, aquatic habitats and have a low reproductive potential.

One male and one female Neotropical otter were captured near Caucasia, Colombia, and taken to Santa Fe Zoological Park in 1994 and 1996, respectively. Zoo staff observed the pair mating in the water, then separated the animals. The female had three births; one was successful. The infant deaths may have been unintentionally caused by the mother. One idea suggested the mother's enclosure was too small and she had no access to water, as she would have had in the wild. The mother's gestation period was 86 days for two separate breeding events recorded at this zoo. An 86 day gestation period is much longer than the previously accepted belief that gestation lasts around 60 days. Two possible explanations are: differences might exist between different subspecies or a later copulation may have occurred and not been observed. Also, this otter species might display short term variation in gestation periods.